1. Field of the Invention
This invention relates generally to a bladed wheel tractor and more particularly to a tractor and tractor wheel of the type which disintegrates material on the ground.
2. Description of the prior art
For many years tractors have employed wheels having blades mounted to the wheel rim at oblique angles with respect to the rim and the wheel axes. Such devices are exemplified in U.S. Pat. No. 1,341,093, 1,475,544 and 3,012,824. The initial purpose in having the blades extend obliquely of the wheel axes was to provide enhanced traction. Recently, as disclosed by U.S. Pat. No. 3,687,023, such bladed wheels have been used for the purpose of chopping previously cut farm and forestry products. For this a plurality of chopper blade wheels are preferably used with the oblique angle mountings of the blades on one wheel transverse to the oblique angle mounting of the blades on that wheel which precedes or follows it. With this arrangement a criss-cross chopping of farm and forestry products lying upon the ground terrain may be made.
Though the just described obliquely mounted bladed wheels of the prior art have functioned satisfactorily, they have been difficult and expensive to manufacture. Perhaps the foremost reason for this is attributable to the fact that rectangular blades can only be mounted axially upon a cylindrical wheel rim for complete mutual abutment between confronting surfaces to occur. Once a significantly oblique angle mounting is introduced it becomes impossible to have a planar edge of the bladed wheel abut the cylindrical wheel rim at more than a single tangential point of mutual contact. As the oblique angle increases, spacial separations between such blade and rim combination increases, rendering even the use of filling or welding material unfeasible. To overcome this, the edges of the blades to be mounted on the cylindrical rim have to be curved with the degree of curvature dependent upon the obliqueness of the angle. Formation of such a curved surface is more difficult as also is the mounting with the two surfaces in complete abutment. In addition, these prior art structural assemblies have also failed frequently from lack of rigidity or structural integrity. Furthermore, mud has also tended to accumulate extensively below the obliquely mounted blades or rim. Also, the blades themselves are difficult to sharpen.